Fix build on arch where python 3 is default

Patch by Jimmy Buse
Copypasta went stale, I had to throw it out.

This commit removes the hardcoded see avatars text that replaced the label of the checkbox on the about land floater regardless of conditions.
Also adds the checkbox translation from v3 for Portuguese.
More comment fixes to refer to services instead of hostnames.
Merge remote-tracking branch 'singu/master'
Always add new http requests to the back the queue.
Add setting to prevent script errors from stealing focus
Change CurlConcurrentConnectionsPerService to U16 and clamp it between 1 and 32.

Also fixes a bug where going from 1 to 2 would not update
AIPerService::mConcurrectConnections correctly.
Add AIPerService::CapabilityType::mConcurrectConnections

Prepares for throttling number of connections per capability type.
The value is current left at AIPerService::mConcurrectConnections,
so not having an effect yet.
Switched the Ascent Prefs callbacks over to modern boost::bind

It's simple to compile fix, but I'll handle any necessary merge conflicts, if necessary.
Hunspell stuff needs revisiting still, works as poorly as it always did.
Removed the need for LLPanelAvatarNotes::onCommitNotes with a bind
Update/Modernize LLFloaterColorPicker

Not very important, just something I did while working on the related spinner bug..
This actually fixed the crash when using the hex editor field.
Update childSetCommitCallback to upstream version, fixes the issue of crashing out upon using spinners in the colorpicker
Fix the issue reported in group chat in which closing preferences with Device Settings open does not return to local voice
Add AIPerService::mCTInUse and AIPerService::mUsedCT

Keep track of which capability types are used and in use
at the moment for each service.

Update the http debug console to only show services
that have at least one capability type marked as used (this resets upon
restart of the debug console) and show previously used but currently
unused capability types in grey.

Update CapabilityType::mConcurrentConnections based on usage of the
capability type (CT): Each currently in-use CT gets an (approximate)
equal portion of the available number of connections, currently
unused CTs get 1 connection for future use, so that requests can and
will be added to them if they occur. If a CT is currently not in use
but was used before then it's connection (but at most one connection)
is kept in reserve. For example, if there are 8 connections available
and a service served textures and mesh in the past, but currently
there are no texture downloads, then mesh get at most 7 connections,
so that at all times there is a connection available for textures.
When one texture is added, both get 4 connections.
Fix documentation at top of AIPerService::approveHTTPRequestFor
Actually use CapabilityType::mConcurrentConnections for Approvements.
Bug fix and improvement (HTTP debug console)
Merge remote-tracking branch 'aleric/master'
Fix the crash upon hitting select for an object's light color feature

Modernizes LLTextureControl(, LLFloaterTexturePicker) and LLColorSwatch
Updates LLPanelVolume, LLPanelObject, and LLPanelFace to prevent related crashes and compile.

Adds translation string InventoryNoTexture to strings.xml (added to all existing translations from upstream translation)
Removed setCallbackUserData calls from the last few newview files